/*
* loop_main.h
*
* Written by Theodore Ts'o, 3/29/93.
*
* Copyright 1993 by Theodore Ts'o. Redistribution of this file is
* permitted under the GNU General Public License.
*/
#ifndef _LINUX_LOOP_H
#define _LINUX_LOOP_H
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <uapi/linux/loop.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#endif
#include "loop_file_fmt.h"
// See: https://www.kernel.org/doc/Documentation/admin-guide/devices.txt
#define XLOOP_MAJOR 120
#define XLOOP_CTRL_MINOR 142
/* Possible states of device */
enum {
Lo_unbound,
Lo_bound,
Lo_rundown,
};
struct loop_func_table;
struct xloop_info {
int lo_number; /* ioctl r/o */
__kernel_old_dev_t lo_device; /* ioctl r/o */
unsigned long lo_inode; /* ioctl r/o */
__kernel_old_dev_t lo_rdevice; /* ioctl r/o */
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size; /* ioctl w/o */
int lo_flags; /* ioctl r/o */
char lo_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
unsigned long lo_init[2];
char reserved[4];
int lo_file_fmt_type;
};
struct xloop_info64 {
__u64 lo_device; /* ioctl r/o */
__u64 lo_inode; /* ioctl r/o */
__u64 lo_rdevice; /* ioctl r/o */
__u64 lo_offset;
__u64 lo_sizelimit;/* bytes, 0 == max available */
__u32 lo_number; /* ioctl r/o */
__u32 lo_encrypt_type;
__u32 lo_encrypt_key_size; /* ioctl w/o */
__u32 lo_flags; /* ioctl r/o */
__u8 lo_file_name[LO_NAME_SIZE];
__u8 lo_crypt_name[LO_NAME_SIZE];
__u8 lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
__u64 lo_init[2];
__u32 lo_file_fmt_type;
} __attribute__((packed));
struct loop_device {
int lo_number;
atomic_t lo_refcnt;
loff_t lo_offset;
loff_t lo_sizelimit;
int lo_flags;
int (*transfer)(struct loop_device *, int cmd,
struct page *raw_page, unsigned raw_off,
struct page *loop_page, unsigned loop_off,
int size, sector_t real_block);
char lo_file_name[LO_NAME_SIZE];
char lo_crypt_name[LO_NAME_SIZE];
char lo_encrypt_key[LO_KEY_SIZE];
int lo_encrypt_key_size;
struct loop_func_table *lo_encryption;
__u32 lo_init[2];
kuid_t lo_key_owner; /* Who set the key */
int (*ioctl)(struct loop_device *, int cmd,
unsigned long arg);
struct loop_file_fmt *lo_fmt;
struct file * lo_backing_file;
struct block_device *lo_device;
void *key_data;
gfp_t old_gfp_mask;
spinlock_t lo_lock;
int lo_state;
struct kthread_worker worker;
struct task_struct *worker_task;
bool use_dio;
bool sysfs_inited;
struct request_queue *lo_queue;
struct blk_mq_tag_set tag_set;
struct gendisk *lo_disk;
#ifdef CONFIG_DEBUG_FS
struct dentry *lo_dbgfs_dir;
#endif
};
struct loop_cmd {
struct kthread_work work;
bool use_aio; /* use AIO interface to handle I/O */
atomic_t ref; /* only for aio */
long ret;
struct kiocb iocb;
struct bio_vec *bvec;
struct cgroup_subsys_state *css;
};
/* Support for loadable transfer modules */
struct loop_func_table {
int number; /* filter type */
int (*transfer)(struct loop_device *lo, int cmd,
struct page *raw_page, unsigned raw_off,
struct page *loop_page, unsigned loop_off,
int size, sector_t real_block);
int (*init)(struct loop_device *, const struct xloop_info64 *);
/* release is called from loop_unregister_transfer or clr_fd */
int (*release)(struct loop_device *);
int (*ioctl)(struct loop_device *, int cmd, unsigned long arg);
struct module *owner;
};
int xloop_register_transfer(struct loop_func_table *funcs);
int xloop_unregister_transfer(int number);
#endif
